I've got a beautiful Calico Cochin pullet that just started laying a couple of weeks ago. She's been pretty consistent until this week. Yesterday and today she went into the nest box and sat there for an hour or two but never laid an egg! When she comes out, she's fine. Eats well, taking 'dust baths' in the deep shavings. No sign of distress but no egg and lots of time in the nest box. Is this normal? Should I be concerned?